This application is a continuation of application Ser. No. 558,495 filed Dec. 6, 1983, now abandoned.
1. Field of the Invention
This invention relates to the purification of brominated aromatic compounds. More particularly, this invention relates to a process for purifying brominated aromatic compounds containing impurities such as residual free bromine and by-product hydrogen bromide. Crude decabromobiphenyl oxide readily lends itself to this purification procedure since it is a solid, thermally stable compound.
2. Description of the Prior Art
Traditional purification techniques are not successful with all brominated aromatic compounds. Recrystallization in particular is often difficult. Decabromobiphenyl oxide has limited solubility in available solvents thus making recrystallization both cumbersome and uneconomical.
U.S. Pat. No. 4,327,227 describes a process for producing purified brominated aromatic compounds. The purification process involves sequentially grinding and then heating the crude solid brominated aromatic compounds. However, this process involves two distinct steps and is not the most efficient and economically desirable means of accomplishing the purification. Considerable handling and hence increased investment would be required if separate drying and grinding process steps were employed.
It has been discovered that by simultaneously drying and grinding a crude solid brominated aromatic compound that a superior brominated aromatic compound can be obtained.
Accordingly, it is a primary object of this invention to teach a process for producing purified brominated aromatic compounds that is superior to the techniques that heretofore have been employed. A two-fold advantage is obtained. The process is more economically attractive and a superior purified product results.